Contribution of point sources and diffuse sources to nitrogen and phosphorus loads in lowland river tributaries
Contribution of point sources and diffuse sources to nitrogen and phosphorus loads in lowland river tributaries
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DOI：
10.1016/s0022-1694(02)00350-5
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发表时间：
2003-02
影响因子：
6.4
通讯作者：
N. Pieterse;W. Bleuten;S. E. Jørgensen
中科院分区：
文献类型：
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作者：
N. Pieterse;W. Bleuten;S. E. Jørgensen
人类活动可能导致流水中总氮（TN）和总磷（TP）负荷增加，从而对其生态质量产生严重影响。氮和磷的可能来源是工业、住宅和农业。提出了基于 GIS 的模型来分析这些来源中哪些来源导致了主要问题。将模拟浓度与代表自来水自然条件的 TN 和 TP 标准进行比较。该模型应用于多梅尔河（比利时/荷兰）受到强烈干扰的流域。人们考虑到河流沉积物可能充当营养物质的汇。来自点源和住宅的流量取自数据库。假设扩散源是人为输入的百分比，定义为土壤养分输入减去作物产量。对 10 个没有点源的源头进行的回归分析表明，5.5% 的人为氮和 0.02% 的人为磷已淋失到河网中。将模型应用于多梅尔河的所有支流，在观测到的 TN 和 TP 负荷与模拟的 TN 和 TP 负荷之间得到了良好的拟合（R2 分别为 0.88 和 0.95）。所有分析的支流均超过 TN 和 TP 标准。分析表明，总体而言，点源是养分通量的主要贡献者，尽管它们只影响少数支流。大多数中小支流受到农业牧场漫流的影响（24.2kg TN ha−1yr−1；0.82kg TP ha−1yr−1）。可以说，减少点源可能有助于最大限度地减少流域规模上的养分通量，减少散源可能有助于恢复个别支流规模上的良好水质。
Human activities may cause enhanced loads of total N (TN) and total P (TP) in running waters, which may have a serious impact on their ecological quality. Likely sources for N and P are industries, dwellings and agriculture. A GIS based model is proposed to analyse which of these sources cause the main problems. Simulated concentrations were compared with standards for TN and TP representing natural conditions in running water. The model was applied on the strongly disturbed catchment of the river Dommel (Belgium/The Netherlands). It was taken into account that river sediments may act as a sink for nutrients. Flows from point sources and dwellings were taken from databases. Diffuse sources were assumed to be a percentage of the anthropogenic input, defined as the nutrient input on the soil minus crop yield. A regression analysis on ten headwaters without point sources suggests that 5.5% of anthropogenic N and 0.02% of anthropogenic P has leached to the river network. Applying the model for all tributaries of the Dommel yielded a good fit between observed and simulated TN and TP loads (R2of 0.88 and 0.95, respectively). All analysed tributaries exceed the standards for TN and TP. Analysis suggests that point sources are -overall- the main contributor to nutrient fluxes, although they affect few tributaries only. Most intermediate and small tributaries are affected by diffuse flows from agricultural pastures (24.2kg TN ha−1yr−1; 0.82kg TP ha−1yr−1). It can be argued that reduction of point sources may help to minimise the magnitude of the nutrient fluxes on the catchment scale, reduction of diffuse sources may help to restore a good water quality on the scale of individual tributaries.